The present invention has for a subject matter a method for detecting a source of heat which may occur in a predetermined area, zone or space, possibly of great extent, particularly a fire in a forest, and a system for carrying out the said method.
The method and system used nowadays to this end, more particularly for detecting a forest fire, may be summed up as follows.
When the weather conditions are propitious to the outbreak or spread of fires, the forest area concerned is placed under watch. A certain number of observation towers or stations of relatively great height are distributed within the area. At the top of each tower, a fireman scrutinizes the horizon in order to visually detect a column of smoke whose localization is not entered on a watcher list which is in the watchman's possession and indicating the existence of a fire. If he discovers such a fire, he will warn the forest fire brigade center through a telephone link. At this center, the identified direction is marked and, after the reception of a call from a nearby tower, the location of the marked fire is performed by way of triangulation. For pointing accuracy considerations, the intervention of a third tower is necessary or at least desirable. It is seen that this watching method and device suffer particularly from the following major drawbacks:
watching limited in time (in daytime and depending on the weather conditions - fog); PA1 difficulty of regular systematic observation along the whole horizon, due to the human factor; PA1 problem of pointing accuracy; PA1 difficulty of observation of the importance and nature of the fire; PA1 necessity for human selection between authorized smoke and fire; PA1 absence of indication as to the direction of spread of the fire; PA1 necessity for awaiting at least a second piece of information from another tower; PA1 turnover of considerable personnel.